1. Field of the Invention
This invention relates to prosthetic appliances and, more particularly, to a flexible prosthetic foot.
2. Description of the Prior Art
U.S. Pat. No. 4,547,913 (Phillips) relates to a composite prosthetic foot and leg which includes three portions, a leg portion, a foot portion, and a heel portion. The three portions are joined together rigidly. The three elements provide a degree of flexibility in response to ankle movements and foot movements, but provide sidewise rigidity. Various embodiments are disclosed.
U.S. Pat. No. 4,822,363 (Phillips) provides a different embodiment by the same inventor as the '913 patent, discussed above. The apparatus is made of laminated material to provide a prosthetic leg connected to a prosthetic foot. The leg portion is curved to define the foot, with a separate head portion connected to the foot portion. Various stiffness may be provided in the foot portion. Again different embodiments are disclosed.
U.S. Pat. No. 5,062,859 (Naeder) discloses a prosthetic foot which includes a resilient foot insert. The foot insert is of a general "Z" configuration. Different embodiments are illustrated.
U.S. Pat. No. 5,156,631 (Merlette) discloses a prosthetic foot and leg in which a leg element curves to define a foot element, and a separate segment is bonded to the forward extending foot portion extension of the leg element. The separate foot portion comprises or defines a sole element.
U.S. Pat. No. 5,258,039 (Goh et al) discloses a prosthetic foot apparatus made of resin impregnated woven fabric material. The apparatus is made of two segments both of which are curved to define a foot and heel portion and which provides the substantial degree of flexibility. Various embodiments or configurations are disclosed.
U.S. Pat. No. 5,376,140 (Ryan) discloses a prosthetic foot apparatus made of composite material. The apparatus has a general configuration of a natural foot with various elements involved, including a foamed polymer body, and cushioning material provides elasticity and flexion.
U.S. Pat. No. 5,486,209 (Phillips) discloses a prosthetic foot apparatus made of laminated materials. The apparatus includes an ankle portion, a foot portion, and a heel portion. Various configurations are illustrated.
U.S. Pat. No. 5,507,838 (Chen) discloses an artificial foot apparatus having a foot shaped casing and insert elements into the casing.
U.S. Pat. No. 5,549,714 (Phillips) discloses another prosthetic foot apparatus made of different elements secured together. Various elements are interchangeable to match the weight, stride, and activity schedule of the user of the apparatus.
U.S. Pat. No. 5,593,456 (Merlette) discloses another prosthetic leg and foot apparatus made of a single monolithic elongated composite member. The member includes a semi-flexible shank portion, an ankle portion, a fore-foot portion, and a toe portion. The apparatus is designed primarily for athletic type use.
U.S. Pat. No. 5,593,457 (Phillips) discloses apparatus similar to that disclosed in the above referred '290 patent. Both the '290 patent and the '457 patent are continuations of the same parent application.